The document discusses disasters and their impacts. It defines a disaster as a sudden event that disrupts normal life and exceeds available resources. Disasters can be natural or man-made. The impacts of disasters include physical damage and injury as well as social and economic disruption. A disaster impact assessment evaluates development projects to identify risks and ways to reduce damages from potential disasters. It considers natural hazards like floods as well as technological hazards caused by infrastructure failures. The assessment aims to incorporate appropriate countermeasures into project design, construction, and management.

1. Disaster Preparedness &
Planning
(PCC-CE-305/OEC-CE502)
DISASTERS IMPACTS

2.  What is a Disaster?
 A disaster is a result of natural or man-made causes that leads
to sudden disruption of normal life, causing severe damage to
life and property to an extent that available social and
economic protection mechanisms are inadequate to cope.
 It is an undesirable occurrence resulting from forces that are
largely outside human control. It strikes quickly with little or
no warning and requires major efforts in providing statutory
emergency service.

3.  Classification of Disasters
 Disasters are classified as per origin, into natural and man-made
disasters. As per severity, disasters are classified as minor or major (in
impact).
 Natural disasters are sudden ecological disruptions or threats that
exceed the adjustment capacity of the affected community and require
external assistance.
 Natural disasters can be broadly classified into categories including
geophysical such as earthquakes and volcanic eruptions; hydrological
such as floods; meteorological such as hurricanes; climatological such
as heat and cold waves and droughts; and biological such as epidemics.
 Man-made disasters can include hazardous material spills, fires,
groundwater contamination, transportation accidents, structure
failures, mining accidents, explosions and acts of terrorism.

4.  Causes for Occurrence of Disaster
 Environmental degradation: Removal of trees and forest cover from a
watershed area have caused, soil erosion, expansion of flood plain area
in upper and middle course of rivers and groundwater depletion.
 Developmental process: Exploitation of land use, development of
infrastructure, rapid urbanization and technological development have
caused increasing pressure over the natural resources.
 Political issues: War, nuclear power aspirations, fight between countries
to become super power and conquering land, sea and skies. These have
resulted into wide range of disaster events such as Hiroshima nuclear
explosion, Syrian civil war, growing militarisation of oceans and outer
space.
 Industrialization: This has resulted into warming of earth and
frequency of extreme weather events has also increased.

5.  Causes for Occurrence of Disaster
 Environmental degradation: Removal of trees and forest cover from a
watershed area have caused, soil erosion, expansion of flood plain area
in upper and middle course of rivers and groundwater depletion.
 Developmental process: Exploitation of land use, development of
infrastructure, rapid urbanization and technological development have
caused increasing pressure over the natural resources.
 Political issues: War, nuclear power aspirations, fight between countries
to become super power and conquering land, sea and skies. These have
resulted into wide range of disaster events such as Hiroshima nuclear
explosion, Syrian civil war, growing militarisation of oceans and outer
space.
 Industrialization: This has resulted into warming of earth and
frequency of extreme weather events has also increased.

6. Disaster impacts
Disaster impacts individuals physically (through loss
of life, injury, health, disability) as well as
psychologically. ... Disaster can alter the natural
environment, loss of habitat to many plants and
animals and cause ecological stress that can result in
biodiversity loss.

17. Physical and Socio-economic Impacts of
Disasters
•Physical impact: death and injury of people and damage to
built environment.
•Rapid Assessment: a quick assessment of a disaster site
immediately after a disaster, to determine immediate needs of
people in impacted area.
•Social impact disruption to essential goods and services
•Built environment includes things such as buildings,
infrastructure, houses etc in an area.

18. Physical Impacts of Disasters
•The physical impacts of a disaster are the deaths and injuries,
and the damage to property and the built environment.
Infrastructure: Infrastructure includes the basic facilities,
services and installations required for the functioning of a
community or a society. Examples of critical infrastructure
components include:
1. Transport system (land, sea and air)
2. Gas and oil storage and transportation

19. Physical Impacts of Disasters….Cont.
3. Communication
4. Electricity, Water supply system, and Public health
5. Security
6. Physical Security
a. Looting of retail outlets and business houses
b. Security of women and children
c. Security of aid workers
7. Emotional security

20. Social Impacts of Disasters
1. Welfare
Welfare falls into the socioeconomic and socio-political category. On the socioeconomic
front this is represented by significant losses to Gross Domestic Product of the affected country
or region. The local and national economy can experience low productivity, price slump, high
unemployment and inflation.
2. Economic Impacts
Economic costs of disasters vary across space and time. Evidence suggests a strong correlation
between a country’s level of development and disaster risk.
Example: In Bangladesh, floods during the Monsoon season destroyed crops and disrupted the
non-farm economy of the country even after the flood waters receded.
Another example is the great Hanshin earthquake in Japan in 1995 that caused $US 100 billion
dollars damage which was equivalent to 2.1% of Japan’s GDP.

21. How Earthquakes Impact the
Environment
1. Collapsing buildings
2. Property damage
3. Mud slides
4. Fires
5. Floods
6. Tsunamis
7. Loss of power

23. Disaster Impact Assessment (DIA)
Disaster Impact Assessment (DIA) is a methodology to
assess development projects from the viewpoint of disaster
risk reduction by identifying improvement points of the
projects.
Based on the findings, revisions to the projects will be
incorporated for reduction of disaster risks and mitigation
of potential effects happened to and from the project
activities.

24. Importance of Disaster Impact Assessment
(DIA)
Disasters can create considerable damages and losses related to
development projects. Therefore, measures to be taken from the beginning
of any development activities to avoid such impacts.
With the aim of minimizing the damages and losses, actions such as
analyses the causal factors of the disasters, anticipated damages and
appropriate countermeasures are required at each stage of the projects.
If the DIA system is incorporated into the processes in development
projects, the extent of damages and losses could be avoided or minimized at
higher degrees. Therefore, Disaster Impact Assessment (DIA) for
evaluating project takes a high importance in its existence.

25. Classification of the Disasters for DIA
According to the DIA considerations for any development sector, the foremost
fact to be considered is to define and differentiate the types of disasters more
clearly.
Related to the development projects, there are three types of disaster situations.
The first situation is a disaster caused by development actions to the
surrounding area. Second is disasters happened to the development action
itself. And the third is a disaster to the surrounding area caused by the
development action which had been damaged by disasters.
In case of second and third situations, the development actions are influenced by
natural phenomena whereas, in the first situation, the cause is technical failure.

27. Classification of the Disasters for
DIA….Cont.
These two types of disasters can be defined as; Natural disasters and
Technological disasters. In brief, natural disasters are originated due to
natural happenings while technological disasters are created due to human
interferences and/or technological failures.
There are key differences of the natural and technological disasters.
Natural hazards such as floods, tsunami, and cyclone are impossible to
control. Technological hazards are possible to control with technological
adjustments and well − managed human interference.

28. Classification of the Disasters for DIA….Cont.
As an example; if rainfall is extremely heavy, area near a culvert of a road
may get inundated because of the size is not at sufficient capacity to drain
off the volume of the upstream water accumulated. This situation was
created by the heavy rainfall and it acts as the natural hazard.
If the rainfall is at normal level but the area near the culvert gets
inundated because of the too small size of the culvert or the disturbed
condition of the culvert with mud. In such cases, inundation can be
considered as a technological disaster.
Technological disasters can be further divided into two types.
Type 01 is identified as disasters associated with the design and
construction such as setting of design conditions. These design conditions
are considered at design stage.
Type 02 is referred to as disasters associated with the management and
maintenance of the projects.

29. Assessment Point of DIA
Two assessment points are prepared to assess with respect to the above two
types of disasters.
Key considerations in DIA for the natural disasters is to check whether the
countermeasures against foreseeable disasters are reflected in the
management plan, usable condition and evacuation plan.
Key considerations in DIA for the technological disasters is to check
whether the design is satisfied at required levels of design standards. In
those considerations, structural countermeasures are considered in the
designs.

30. Assessment Point of DIA…..Cont.

31. Outcome of Disaster Impact Assessment (DIA)
Consideration of conditions at design and construction stages is helpful to
prepare appropriate countermeasures for disasters in advance.
As examples, inclusion of structural countermeasures in the design can be
highlighted.
It helps to set design conditions at higher levels.
Nonstructural countermeasures such as evacuation plans, early warning
mechanisms can also be proposed accordingly.
By those countermeasures, disaster damages on development projects can be
mitigated.